1. Field of the Invention
The present invention relates to an image data recording medium consisting of a leader tape, a magnetic tape and a continuous tape, which are spliced together successively in that order. The present invention also pertains to an apparatus for determining the position of the magnetic tape of the image data recording medium.
2. Description of the Related Art
One type of image data recording medium has heretofore been devised which consists of an electrophotographic film and a magnetic film spliced to each other so that images are recorded on the electrophotographic film and image data is recorded on the magnetic tape. This type of image data recording medium has been disclosed in U.S. Pat. No. 4,561,769 which is an invention regarding a system for retrieval of a micro image.
This type of image data recording medium is accommodated in a cassette, and it is possible to record images on the electrophotographic film of the recording medium at random for each cassette. Further, it is possible to readily retrieve any desired image recorded on the electrophotographic film on the basis of the image data recorded on the magnetic tape and further to project the retrieved image on a screen.
To spot the position of the magnetic tape, one type of magnetic tape position determining apparatus has already been proposed in which a reflection photosensor is disposed so as to face a magnetic tape having pieces of reflecting paper, e.g., pieces of aluminum foil, which are respectively stuck to the starting and terminating ends thereof.
One type of a cassette which is capable of accommodating therein the image data recording medium according to the present invention has been disclosed in U.S. Pat. No. 4,572,649, and one type of a processing head which is suitably applied to record micro images on the image data recording medium according to the present invention has been disclosed in U.S. Pat. No. 4,600,291.
Also, there are U.S. application Ser. Nos. 884,344 and 819,077 as U.S. applications relating to the present invention.
In the conventional apparatus, the pieces of aluminum foil are detected by the reflection photosensor in order to detect the starting and terminating ends of the magnetic tape, thereby determining the position of the magnetic tape.
However, the prior art suffers from the following problems. Since aluminum foil is bonded to the starting end of the magnetic tape, when this end of the tape is rigidly secured to a reel of a cassette and the tape is wound up on the reel, the roll of wound tape undesirably has a step at the position of the aluminum foil, and this leads to deterioration of the magnetic tape. Further, in order to make discrimination between the starting and terminating ends of the magnetic tape, it is necessary to stick two pieces of aluminum foil at positions which are different from each other in the widthwise direction of the magnetic tape and to dispose two reflection photosensors at positions which are different in the widthwise direction of the tape so that the two photosensors respectively face the pieces of aluminum foil, which means that the arrangement of the apparatus is complicated, disadvantageously.